RNA Expression Profiling Core. A comprehensive analysis of RNA expression in distinct cell types has been revolutionized by the use of DNA microarray analysis. This methodology can assess the expression patterns of thousands of genes in quantitative terms with small amounts of cells or tissue. This analysis seeks to develop genetic markers for the models under study in each aim in the in vitro and in vivo analyses that form the basis of this proposal. Identification of such markers can then be used to facilitate the validation of the hypotheses of these models. The use of RNA markers should be a reliable method for defining cellular expression profiles. Once a set of markers has been identified these sequences can then be used by additional methods (e.g., in situ hybridization) to further test the hypotheses. Core E will work with investigators in Projects 1 and 2 to identify markers from cultured cells and from experimentally manipulated vascular tissues that can be compared with RNA prepared from human GA and control arteries in Core D.